Revision total knee or hip replacement is becoming increasingly common with the success of the procedure, the aging population, and more frequent use in younger individuals. Management of bone loss and optimizing stability and function are important challenges faced during revision total knee and hip replacement. Porous or porous coated metal knee cones or acetabular augments, custom porous coated cups, and acetabular reconstruction cages are available in the industry to accommodate areas of bone loss. Short and intermediate-term studies demonstrate acceptable outcomes in the setting of bone loss during revision total knee or hip replacement using traditional porous cones and augments. Particularly, these cones or augments allow biologic fixation with bone healing directly to the porous augment, porous cone or sleeve, replacing areas of bone loss while enhancing fixation and allowing restoration of a more normal knee joint line or more normal hip center of rotation.
Traditional porous cones are generally inserted into the area of bone loss and centered within the cavity by the remaining bone, the cone maintaining its position via a friction fit. If bone loss in the host occurs only on one side of the cavity, removal of healthy bone is performed on the opposing side to ensure proper centering of the cone within the cavity. Upon forming the cavity and introducing the cone, stable contact between the remaining bone and the cone may not occur due to the configuration of the cavity. Such failed contact can result in extended time for bone in-growth or failure of bone in-growth at certain surfaces of the cone. Traditional cones also do not provide a means for attachment of avulsed or fractured bone with important ligament and/or tendon attachments, such as the femoral epicondyle(s) or tibial tubercle.
Thus, a need exists for improved augments that can be introduced into differently sized cavities without extensive removal of healthy bone, augments that ensure direct and/or stable contact with the remaining bone of the cavity, and augments that reliably attach important fractured metaphyseal bone segments. These and other needs are addressed by the augments and methods of the present disclosure.